[PATCH v6 4/8] crypto: x86/twofish: Remove glue function macro usage

Kees Cook
2019-11-22T01:03:43Z

In order to remove the callsite function casts, regularize the function
prototypes for helpers to avoid triggering Control-Flow Integrity checks
during indirect function calls. Where needed, to avoid changes to
pointer math, u8 pointers are internally cast back to u128 pointers.

Co-developed-by: João Moreira <joao.moreira@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
arch/x86/crypto/twofish_avx_glue.c | 75 ++++++++++++---------------
arch/x86/crypto/twofish_glue_3way.c | 37 +++++++------
arch/x86/include/asm/crypto/twofish.h | 19 +++----
3 files changed, 61 insertions(+), 70 deletions(-)

diff --git a/arch/x86/crypto/twofish_avx_glue.c b/arch/x86/crypto/twofish_avx_glue.c
index d561c821788b..3b36e97ec7ab 100644
--- a/arch/x86/crypto/twofish_avx_glue.c
+++ b/arch/x86/crypto/twofish_avx_glue.c
@@ -22,20 +22,17 @@
#define TWOFISH_PARALLEL_BLOCKS 8

/* 8-way parallel cipher functions */
-asmlinkage void twofish_ecb_enc_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
-asmlinkage void twofish_ecb_dec_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
+asmlinkage void twofish_ecb_enc_8way(const void *ctx, u8 *dst, const u8 *src);
+asmlinkage void twofish_ecb_dec_8way(const void *ctx, u8 *dst, const u8 *src);

-asmlinkage void twofish_cbc_dec_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
-asmlinkage void twofish_ctr_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src, le128 *iv);
+asmlinkage void twofish_cbc_dec_8way(const void *ctx, u8 *dst, const u8 *src);
+asmlinkage void twofish_ctr_8way(const void *ctx, u8 *dst, const u8 *src,
+ le128 *iv);

-asmlinkage void twofish_xts_enc_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src, le128 *iv);
-asmlinkage void twofish_xts_dec_8way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src, le128 *iv);
+asmlinkage void twofish_xts_enc_8way(const void *ctx, u8 *dst, const u8 *src,
+ le128 *iv);
+asmlinkage void twofish_xts_dec_8way(const void *ctx, u8 *dst, const u8 *src,
+ le128 *iv);

static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
const u8 *key, unsigned int keylen)
@@ -43,22 +40,19 @@ static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
return twofish_setkey(&tfm->base, key, keylen);
}

-static inline void twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src)
+static inline void twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src)
{
__twofish_enc_blk_3way(ctx, dst, src, false);
}

-static void twofish_xts_enc(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void twofish_xts_enc(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
{
- glue_xts_crypt_128bit_one(ctx, dst, src, iv,
- GLUE_FUNC_CAST(twofish_enc_blk));
+ glue_xts_crypt_128bit_one(ctx, dst, src, iv, twofish_enc_blk);
}

-static void twofish_xts_dec(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+static void twofish_xts_dec(const void *ctx, u8 *dst, const u8 *src, le128 *iv)
{
- glue_xts_crypt_128bit_one(ctx, dst, src, iv,
- GLUE_FUNC_CAST(twofish_dec_blk));
+ glue_xts_crypt_128bit_one(ctx, dst, src, iv, twofish_dec_blk);
}

struct twofish_xts_ctx {
@@ -93,13 +87,13 @@ static const struct common_glue_ctx twofish_enc = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_ecb_enc_8way) }
+ .fn_u = { .ecb = twofish_ecb_enc_8way }
}, {
.num_blocks = 3,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_3way) }
+ .fn_u = { .ecb = twofish_enc_blk_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk) }
+ .fn_u = { .ecb = twofish_enc_blk }
} }
};

@@ -109,13 +103,13 @@ static const struct common_glue_ctx twofish_ctr = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_ctr_8way) }
+ .fn_u = { .ctr = twofish_ctr_8way }
}, {
.num_blocks = 3,
- .fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_enc_blk_ctr_3way) }
+ .fn_u = { .ctr = twofish_enc_blk_ctr_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ctr = GLUE_CTR_FUNC_CAST(twofish_enc_blk_ctr) }
+ .fn_u = { .ctr = twofish_enc_blk_ctr }
} }
};

@@ -125,10 +119,10 @@ static const struct common_glue_ctx twofish_enc_xts = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_enc_8way) }
+ .fn_u = { .xts = twofish_xts_enc_8way }
}, {
.num_blocks = 1,
- .fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_enc) }
+ .fn_u = { .xts = twofish_xts_enc }
} }
};

@@ -138,13 +132,13 @@ static const struct common_glue_ctx twofish_dec = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_ecb_dec_8way) }
+ .fn_u = { .ecb = twofish_ecb_dec_8way }
}, {
.num_blocks = 3,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk_3way) }
+ .fn_u = { .ecb = twofish_dec_blk_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk) }
+ .fn_u = { .ecb = twofish_dec_blk }
} }
};

@@ -154,13 +148,13 @@ static const struct common_glue_ctx twofish_dec_cbc = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_cbc_dec_8way) }
+ .fn_u = { .cbc = twofish_cbc_dec_8way }
}, {
.num_blocks = 3,
- .fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk_cbc_3way) }
+ .fn_u = { .cbc = twofish_dec_blk_cbc_3way }
}, {
.num_blocks = 1,
- .fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk) }
+ .fn_u = { .cbc = twofish_dec_blk }
} }
};

@@ -170,10 +164,10 @@ static const struct common_glue_ctx twofish_dec_xts = {

.funcs = { {
.num_blocks = TWOFISH_PARALLEL_BLOCKS,
- .fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_dec_8way) }
+ .fn_u = { .xts = twofish_xts_dec_8way }
}, {
.num_blocks = 1,
- .fn_u = { .xts = GLUE_XTS_FUNC_CAST(twofish_xts_dec) }
+ .fn_u = { .xts = twofish_xts_dec }
} }
};

@@ -189,8 +183,7 @@ static int ecb_decrypt(struct skcipher_request *req)

static int cbc_encrypt(struct skcipher_request *req)
{
- return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(twofish_enc_blk),
- req);
+ return glue_cbc_encrypt_req_128bit(twofish_enc_blk, req);
}

static int cbc_decrypt(struct skcipher_request *req)
@@ -208,8 +201,7 @@ static int xts_encrypt(struct skcipher_request *req)
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct twofish_xts_ctx *ctx = crypto_skcipher_ctx(tfm);

- return glue_xts_req_128bit(&twofish_enc_xts, req,
- XTS_TWEAK_CAST(twofish_enc_blk),
+ return glue_xts_req_128bit(&twofish_enc_xts, req, twofish_enc_blk,
&ctx->tweak_ctx, &ctx->crypt_ctx, false);
}

@@ -218,8 +210,7 @@ static int xts_decrypt(struct skcipher_request *req)
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct twofish_xts_ctx *ctx = crypto_skcipher_ctx(tfm);

- return glue_xts_req_128bit(&twofish_dec_xts, req,
- XTS_TWEAK_CAST(twofish_enc_blk),
+ return glue_xts_req_128bit(&twofish_dec_xts, req, twofish_enc_blk,
&ctx->tweak_ctx, &ctx->crypt_ctx, true);
}

diff --git a/arch/x86/crypto/twofish_glue_3way.c b/arch/x86/crypto/twofish_glue_3way.c
index 1dc9e29f221e..768af6075479 100644
--- a/arch/x86/crypto/twofish_glue_3way.c
+++ b/arch/x86/crypto/twofish_glue_3way.c
@@ -25,21 +25,22 @@ static int twofish_setkey_skcipher(struct crypto_skcipher *tfm,
return twofish_setkey(&tfm->base, key, keylen);
}

-static inline void twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src)
+static inline void twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src)
{
__twofish_enc_blk_3way(ctx, dst, src, false);
}

-static inline void twofish_enc_blk_xor_3way(struct twofish_ctx *ctx, u8 *dst,
+static inline void twofish_enc_blk_xor_3way(const void *ctx, u8 *dst,
const u8 *src)
{
__twofish_enc_blk_3way(ctx, dst, src, true);
}

-void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src)
+void twofish_dec_blk_cbc_3way(const void *ctx, u8 *d, const u8 *s)
{
u128 ivs[2];
+ u128 *dst = (u128 *)d;
+ const u128 *src = (const u128 *)s;

ivs[0] = src[0];
ivs[1] = src[1];
@@ -51,9 +52,11 @@ void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src)
}
EXPORT_SYMBOL_GPL(twofish_dec_blk_cbc_3way);

-void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
+void twofish_enc_blk_ctr(const void *ctx, u8 *d, const u8 *s, le128 *iv)
{
be128 ctrblk;
+ u128 *dst = (u128 *)d;
+ const u128 *src = (const u128 *)s;

if (dst != src)
*dst = *src;
@@ -66,10 +69,11 @@ void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src, le128 *iv)
}
EXPORT_SYMBOL_GPL(twofish_enc_blk_ctr);

-void twofish_enc_blk_ctr_3way(void *ctx, u128 *dst, const u128 *src,
- le128 *iv)
+void twofish_enc_blk_ctr_3way(const void *ctx, u8 *d, const u8 *s, le128 *iv)
{
be128 ctrblks[3];
+ u128 *dst = (u128 *)d;
+ const u128 *src = (const u128 *)s;

if (dst != src) {
dst[0] = src[0];
@@ -94,10 +98,10 @@ static const struct common_glue_ctx twofish_enc = {

.funcs = { {
.num_blocks = 3,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_3way) }
+ .fn_u = { .ecb = twofish_enc_blk_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk) }
+ .fn_u = { .ecb = twofish_enc_blk }
} }
};

@@ -107,10 +111,10 @@ static const struct common_glue_ctx twofish_ctr = {

.funcs = { {
.num_blocks = 3,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr_3way) }
+ .fn_u = { .ctr = twofish_enc_blk_ctr_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_enc_blk_ctr) }
+ .fn_u = { .ctr = twofish_enc_blk_ctr }
} }
};

@@ -120,10 +124,10 @@ static const struct common_glue_ctx twofish_dec = {

.funcs = { {
.num_blocks = 3,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk_3way) }
+ .fn_u = { .ecb = twofish_dec_blk_3way }
}, {
.num_blocks = 1,
- .fn_u = { .ecb = GLUE_FUNC_CAST(twofish_dec_blk) }
+ .fn_u = { .ecb = twofish_dec_blk }
} }
};

@@ -133,10 +137,10 @@ static const struct common_glue_ctx twofish_dec_cbc = {

.funcs = { {
.num_blocks = 3,
- .fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk_cbc_3way) }
+ .fn_u = { .cbc = twofish_dec_blk_cbc_3way }
}, {
.num_blocks = 1,
- .fn_u = { .cbc = GLUE_CBC_FUNC_CAST(twofish_dec_blk) }
+ .fn_u = { .cbc = twofish_dec_blk }
} }
};

@@ -152,8 +156,7 @@ static int ecb_decrypt(struct skcipher_request *req)

static int cbc_encrypt(struct skcipher_request *req)
{
- return glue_cbc_encrypt_req_128bit(GLUE_FUNC_CAST(twofish_enc_blk),
- req);
+ return glue_cbc_encrypt_req_128bit(twofish_enc_blk, req);
}

static int cbc_decrypt(struct skcipher_request *req)
diff --git a/arch/x86/include/asm/crypto/twofish.h b/arch/x86/include/asm/crypto/twofish.h
index f618bf272b90..2c377a8042e1 100644
--- a/arch/x86/include/asm/crypto/twofish.h
+++ b/arch/x86/include/asm/crypto/twofish.h
@@ -7,22 +7,19 @@
#include <crypto/b128ops.h>

/* regular block cipher functions from twofish_x86_64 module */
-asmlinkage void twofish_enc_blk(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
-asmlinkage void twofish_dec_blk(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
+asmlinkage void twofish_enc_blk(const void *ctx, u8 *dst, const u8 *src);
+asmlinkage void twofish_dec_blk(const void *ctx, u8 *dst, const u8 *src);

/* 3-way parallel cipher functions */
-asmlinkage void __twofish_enc_blk_3way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src, bool xor);
-asmlinkage void twofish_dec_blk_3way(struct twofish_ctx *ctx, u8 *dst,
- const u8 *src);
+asmlinkage void __twofish_enc_blk_3way(const void *ctx, u8 *dst, const u8 *src,
+ bool xor);
+asmlinkage void twofish_dec_blk_3way(const void *ctx, u8 *dst, const u8 *src);

/* helpers from twofish_x86_64-3way module */
-extern void twofish_dec_blk_cbc_3way(void *ctx, u128 *dst, const u128 *src);
-extern void twofish_enc_blk_ctr(void *ctx, u128 *dst, const u128 *src,
+extern void twofish_dec_blk_cbc_3way(const void *ctx, u8 *dst, const u8 *src);
+extern void twofish_enc_blk_ctr(const void *ctx, u8 *dst, const u8 *src,
le128 *iv);
-extern void twofish_enc_blk_ctr_3way(void *ctx, u128 *dst, const u128 *src,
+extern void twofish_enc_blk_ctr_3way(const void *ctx, u8 *dst, const u8 *src,
le128 *iv);

#endif /* ASM_X86_TWOFISH_H */
--
2.17.1